The present invention relates to agricultural tool bars. A tool bar for agricultural use is a device which is adapted to be pulled by a tractor and on which ground-engaging implements are mounted. The tool bar supports the implements, and it also maintains a fixed lateral spacing between the implements.
A wide range of implements may be used on agricultural tool bars such as planters for seeds, chizel plows, coulters, or other tillage tools, applicator knives for anhydrous ammonia, or combinations of these. Hence, the word "implements" is intended to have a broad definition to include all of these various devices, as well as others.
In particular, the present invention is directed to improvements in a rear-folding tool bar of the type being manufactured and sold by Kinze Manufacturing, Inc. of Williamsburg, Iowa. In tool bars of this type, first and second wings are pivotally mounted to a main frame which is provided with support wheels. The wings or "bars" are pivoted between a use position in which the wings extend laterally of the main frame and transverse of the direction of travel of the vehicle, and a road travel position in which the wings extend rearwardly of the main frame and parallel to the direction of the vehicle.
In agricultural tool bars, it is desirable that adjacent units or implements mounted on the wings be spaced at the same distance across the entire extended position of the tool bar. This is normally true whether the implements are planters, tillage tools or fertilizer knives. In some prior tool bars, the width of the tool bar is divided into three section--two wings and a fixed center section, which all align in the extended or use position. The center-folding tool bar of the type described above is, however, preferred because its width in the folded position is more convenient for road travel. There is, however, a problem in a center-folding tool bar of this type in that there is a tendency for the innermost units (that is, those mounted on the central sections of the side wings) to interfere with the ground support wheels on the main frame. Various suggestions have been proposed to overcome this problem, including lifting the implements relative to the wings during folding, and lifting the central portions of the entire wings. These solutions overcome the interference problem, but they require hydraulic control systems or methods of mounting the implements that permit them to be raised. In the case of fertilizer knives and the like, which are normally rigidly secured to the wings, it is not possible to raise the implements relative to the wings. Further, in such instances, there is no need for an expensive hydraulic control system for raising the wings high enough that the implements will clear the wheels.
According to the present invention, a cross frame is rigidly mounted to the main frame independently of the folding wings; and it is located at a forward position. That is, it is located forward of the folding wings and also forward of the wheels. The center implements are mounted on the rigid cross frame so that the innermost sections of the folding wings are free of implements, and there is no interference with the wheels of the frame during folding. At the same time, the rigid cross frame will carry a plurality of implements, and the lateral spacing of all adjacent implements will be the same across the entire extended width of the system. This permits the wings to be folded at central positions, while avoiding the interference problem mentioned above. The improved system may be used with different types of implements, and without the need for special hydraulic control system for units to raise the bars so that the implements clear the support wheels.
Other features and advantages of the present invention will be apparent to persons skilled in the art from the following detailed description of a preferred embodiment accompanied by the attached drawing wherein identical reference numerals refer to like parts in the various views.